Aspects of the present disclosure relate generally to optical imaging such as exemplified by methods and systems benefiting from grating-enhanced imaging.
Optical microscopy has experienced a significant growth in the medical and biological sciences during the last decade. The increased importance of optical microscopy has been due to new developments in fluorescent probe technology, and the availability of quantitative three-dimensional image data obtained through either computational deconvolution or scanning confocal microscopy.
Optical microscopy offers several advantages over non-optical microscopy techniques. Use of optical microscopy allows viewing of living tissue samples in their natural state. Electron microscopy, in comparison, requires microscopy samples which are dried and exposed to vacuum. Additionally, the interior of the sample can be viewed and mapped in three dimensions using optical microscopy, whereas scanning electron microscopy and other scanned probe microscopies map only the surface of the sample, and thus cannot provide information about the sample interior.
For improved resolution of imaging systems, beyond the intrinsic cutoff frequency as defined by the numerical aperture and wavelength, various approaches have been previously investigated. These include the use of two static gratings, two moving gratings, structured illumination, and various oblique illumination schemes. In many instances, these techniques are burdensome/complex to implement or are limited by the numerical aperture (NA) of the illumination optics.